The dependence of peak electron density in the ionosphere of Mars on solar irradiance

Abstract

Previous studies of the Mars ionosphere have concluded that increased solar flux leads to increased peak electron densities. Many have described this relationship as Nm ∝ Fk, where Nmis the peak electron density, F, the ionizing flux, is represented by either F 10.7 or E10.7, and k is an exponent. The derived exponents have varied greatly, but have a mean value of k ≃ 0.35. Here, we explore this relationship using solar spectra measurements from the TIMED-SEE instrument and Mars Global Surveyor radio occultation data. Our derived exponents, k ≃ 0.50, are larger than those found by previous studies that used F 10.7or E10.7and are close to the theoretical prediction of simplistic Chapman theory. © 2013 American Geophysical Union. All Rights Reserved.